Conventionally, prevention of combustion gas from leaking to the outside of an internal combustion engine by interposing a seal member between a combustion pressure detection device that is mounted on the internal combustion engine and detects pressure inside a combustion chamber and a structural body which configures the combustion chamber and to which the combustion pressure detection device is attached has been suggested.
For example, a stress detection device described in Patent Document 1 has a housing that is formed into a cylinder and made of a stainless steel, a screw part is formed on the outer circumferential surface of the housing, and the screw part is screwed into a screw hole that is provided to penetrate a cylinder head of an engine block. At this time, a gasket as a seal ring between a hexagonal part of the housing and the engine block is pressed to the outer surface of the cylinder head.